Rostock Confocal Image Analysis of Patients Treated With Cultured Limbal Epithelial Stem Cell Therapy

Abstract

Purpose:: The current techniques available to determine the outcome of cultured limbal epithelial stem cell therapy (LESC) are limited with respect to evaluation of the ocular surface post- cell transplantation. Therefore we evaluated the potential usefulness of clinical confocal microscopy in assessing the outcome of cultured autologous and alogeneic limbal epithelial stem cell (LESC) therapy.

Methods:: LESC harvested from autologous limbal biopsies or cadaveric human corneas were cultured on human amniotic membrane and used to treat 10 pateints (3 autologous and 7 allogeneic) with LESC failure caused by ectodermal dysplasia, chemical or acid injury, Reigers anomaly or aniridia. The Rostock corneal module and Heidelberg HRT-II were used to perform in vivo scanning laser confocal microscopy. In successful cases (defined as restoration of an intact, transparent and avascular corneal epithelium) cell morphology and cell size were evaluated pre-operatively and 6 months post-operatively.

Results:: The clinical success rates at 6 months were overall - 7/10 (70%), autograft - 1/3 (33%) and cadaveric allograft - 6/7 (85%). Of the 7 successful cases, pre and post operative scans were possible in 5 and 6 patients respectively. As would be predicted for LESC failure, pre operative imaging did not identify classic features of corneal epithelium (e.g. hexagonal cells of regular patterning) . However, 6 month post operative scans revealed the presence of cells with characteristics of normal corneal epithelium. In one case a mixed pattern of corneal and conjunctival cell morphologies were observed. Despite the potential usefulness of the method it was found to be limited by factors including patient tolerance, user skill and experience and the data being limited to morpohological analysis only.

Conclusions:: It is technically possible to visualise cultured limbal epithelial cells post transplantation in patients. The Rostock module is a useful and non-invasive tool but currently has limitations in its application for evaluating LESC therapy efficacy. In the future some of these limitations could be overcome if safe and enduring cell labels could be incorporated and imaged during long-term follow up in humans.

Keywords: cornea: epithelium • cornea: clinical science • transplantation